Eccentric Plug Valves
Fisher eccentric plug valves combines globe valve ruggedness with the efficiency of a rotary valve.
Fisher eccentric plug valves combines globe valve ruggedness with the efficiency of a rotary valve.
A style of rotary control valve with a plug-shaped, flow-restricting member that follows an eccentric path as it rotates. The plug has no contact with its seat until it turns within a few degrees of the shutoff position. As the plug contacts or “cams” into the seat, the seating surfaces dynamically align to achieve shutoff. This valve type can also be referred to as rotary globe.
Eccentric plug rotary control valves control erosive, coking, and other hard-to-handle fluids, providing either throttling or on/off operation. The flanged valves feature streamlined flow passages and rugged, metal trim components for dependable service in slurry applications. These valves are used in mining, petroleum refining, power, and pulp and paper industries.
For erosive applications, the recommended flow direction an eccentric plug valve is with the shaft upstream. High velocity flow is isolated in the port or outlet area. Here the seat ring and retainer can be protected by utilizing erosion-resistant materials and can be easily maintained.
Trim materials are selectable for various erosive applications. Plug, seat ring, and retainer are available in hardened materials, including ceramics and carbides, for improved selection of erosion resistance.
A V-notch ball in place of plug allows for the higher capacity and rangeability of a segmented ball valve. The ball cams into and out of the seat minimizing contact with the seat ring for reduced wear and friction.
